1. Field of the Invention
The present invention relates to a narrow wall or slotted wall which is introduced into a geological substratum or foundation, including a sealing wall composition contained therein, and at least one sealing wall plate which, for example, is constituted of glass.
For the protection of the ground water from being polluted with contaminated waters seeping from a refuse or waste depository site, such as landfill or the like, the refuse or waste sites are surrounded with sealing walls.
In order to be able to monitor the sealing function of the sealing wall composition with regard to deformations or shifts in the soil and against chemical corrosions over lengthy periods of time, it is necessary to provide testing or instrumentation systems. This is especially importantly applicable when the sealing walls are constituted from only sealing wall compositions, even when these possess properties of a high degree of impermeability. It is impossible to preclude encountering the presence of fissures or cracks at various locations, into which there can unnoticedly migrate noxious or toxic materials, as well as in the wall itself.
2. Discussion of the Prior Art
It is known that by means of control well points or, in essence, watermark gauges, it is possible that on both sides of the sealing wall there can be tested or sampled the geological substratum conditions by means of physical probes and instrumentation systems. However, it is not possible to preclude that these well points or, in essence, respectively watermark gauges, will be subject to failure or malfunctions over lengthier periods of time because of various reasons. As a consequence thereof, it is absolutely necessary to position the devices for effecting the control measurements into the sealing wall plates themselves. This is also applicable for the encapsulation of presently existing, waste depots or landfills, wherein there is no longer any need to count on deformations or distortions of the sealing wall composition or, in essence, plate.
From the disclosure of European Patent 0298 283 A1 there has become known a structure consisting of a vertical slotted wall and a sealing wall arranged therein, which structure is inserted into a geological substratum, wherein the slotted wall is filled with a composition for forming the slotted wall and the sealing wall is installed in the slotted wall composition. In view of this construction, the invention in the European patent contemplates that the sealing wall is assembled from glass plates which, with the interposition of spacer retainers, are arranged with distancing interspaces whereby also the distancing interspaces are filled with the slotted wall composition.
The sealing along the joints of the individual glass plates can be undertaken in that the individual glass plates of the multi-plate glass units are pushed into contact against each other at the vertical joints, with the interposition of a sealing medium consisting of either rubber or a plastic material, and the thereby formed hollow space at the joints is filled with a bituminous casting composition. The individual glass plates are further positioned on each other along the horizontal joints with the interposition of a sealing web or strip constituted from rubber or from a plastic material, and which strip possess the width of the multi-plate glass units.
This sealing arrangement is extremely complicated in its assembly and introduction thereof into the joints of the installed glass plates, and nevertheless, its sealing effectiveness is not always adequate, especially not at the intersecting locations for the joints.
Also in this instance is it, as a consequence, necessary to be able to determine possible non-sealed or leakage conditions and to display this fact in order to comply within a requisite period of time with precautions or regulations against any penetration of toxic materials into the geological substratum or subsoil.